Field of the Invention
The present application relates to a thin film transistor array substrate, and more particularly to a thin film transistor array substrate adapted to prevent the generation of thickness deviations in an organic emission layer which is included in an organic light emitting diode (OLED) display device with the thin film transistor array substrate.
Description of the Related Art
Display devices include display devices with backlight units and OLED display devices using self-luminous elements that do not require a separated backlight unit. In accordance therewith, an OLED display device using a self-luminous element can be thin and have low power consumption.
The OLED display device can include an organic light emitting element including an anode electrode, a cathode electrode and an organic emission layer interposed between the two electrodes. An organic light emitting element enables generation of excitons by recombining holes and electrons from the anode and cathode electrodes into the organic emission layer. Also, the organic light emitting element emits light by the excitons transitioning from an excited state to a stable state.
The organic emission layer can be formed using a vapor deposition method. An ink-jet printing process can be used to form the organic emission layer on a large-sized substrate by dropping a liquefied organic emission material.
Such an organic emission layer has thicker edge areas adjacent to a bank pattern compared to a central area surrounded by the bank pattern. This results from the fact that the edge portion of the organic emission layer is hardened at a slower speed than a hardening speed of the central portion of the organic emission layer; and an organic emission material is internally removed from the central area of the organic emission layer to the edge area of the organic emission layer due to a hardening phenomenon of the organic emission material progresses from the central area to the edge area of the organic emission layer.